Refrigerator cabinet



Jan. 15, 1952 Q E FRYKDAHL 2,582,862

REFRIGERATOR CABINET Filed Sept. 28, 1946 5 Sheets-Sheet 1 Jan. 15, 1952 c. E. H. FRYKDAHI. 2,582,862

REFRIGERATOR CABINET Filed Sept. 28, 1946 3 Sheets-Sheet 2 'lau-"3 111111111511111" ATTORNEYS Jali- 15, 1952 c. E. H. FRYKDAHL REFRIGERATQR' CABINET Filed sept. 28, 194e 3 Sheets-Sheet 3 NIT ED @SFF-ICE 315.82362 REFRIG-EnAToR`v CABINET `vCari Eawardznrry Frykdan'ltl-Dqintn-iuinp.

' V- -s`iii.f1o1" tofThe f Colerator `Compa fltzlfnn., a corporation Lofp:vv fes'ota Alpplicationgseptember 28,',1946,1 SerialaNo.` .699,979

sonnes (Cineto-15) toune eiiiionltfsoito do inl et nreotieelinenner ,estensori-thomson temple, those materiels This invention-relates tol refrieerntornnd like v ;oebinets embodying inner. andlonter ensngiinnd 4pt imarily.has .do withssnpportfof tnefinner toeliet-f sniieientstrnetnrel strens'tnto tossine, Within the outer easing inieiioh n, eebi- .Ssnnnott the. innerieesine werensnnlly 4inet. 5 of `seein nature, @tient oioieetioneiole neet treinstel A tefrieeratonor like oebinetnsnellynesineo1i11.f .ooo1ir tnerethnoneh andv tnose. ,1neteri e1s .ating material `interposed .betweenthe inner .tWhehhediowineetooninetiityiisiielly--didtnet .gn'dtouter oesines tnereoisonsito enebleeteinpossess the eenisitestrensth to ,insiireproner Vvpertituie `to bemeinteined within theinneix-eesine snneertn t inner tesine f iomtne. outer eesingthetisdifierentfiom tnetsnrronndinethetontei 10. ltisinesiteblennewenen; that the edges --loetween 1veasing,and 'siioh instenoes itisfdesireiele to the oliened onenineseiioreed in -oesins`s. ,of,the ,keepdthe ,nent transfer betweentheutwo ylczasings aforesaid character be closedyuforleianlple. toreeteminiinnmend tneneloy- Ineintein theein i ney i tsin, tne insuletineineteitieiftnet is interposed loethe tweenthe twonesines ntnsasition'-and itist'nenetaqqgsof la, refrigerator Wcabinet, Whig the 15 fore yet another object of this inyentionoyenitemi'oenetore withintne innenoesine oonnnonly ;.eiele-ineterieiiofilowneet eondnetivityfto be intmsintained below theiternnenetnre ,sii-rrotindine hier Seinem@ tnel-edeesiof aligned `nines `.the outer. cosine. heat `transferloettteen tn nenenionter eesinesioi openi- -ings `Ine-y-eive1ise tosweetinetonithe exposed -ohnreeterend yetettheseme surface of the-outerfoesinennder.eertain `oo nflio 'ne tobesnpnertediroin :tiens- It is t he1efore importantn refrieenator erebeineobieetonehle eabinetsiend the like thatnest transfer between `z neetintensieiitzetteen the tireeasings. the innemend onterfoesinsste tkept atie mini- ,rites-oit?, eeeseiyein neirigexator oebinets mum and to V en alole this-:to be realizedginn and `the like to establish` eietricalnonothe n- V@ eiiioientand novetfrnennenis emonetneprfmary 25A-intimen ennemies. diseoseotwithmthe Y bjectsof vthis 1m-3111;i-0r`1- inner casing of such a cabinet anndnpparattis Vclis- Heretoforeinthose instances `wherernetet11-ie or P 0S ed :;e 5teie1ly,sot Jsneninner easing; and Vit is .rf-ether leesings nei/ineseletivelyhiehfheat eontiiio- 1 .ofittn esittiloie. to, .eiiotd eeeess teelten ,eonneotiv'ity- Ahave been emnloyed fin` oeloinets. ofizthe eindmentions-$et nnother object of this V aforesaidharacterithasbeen cnstomaryitocem- 30 invention is to enable electrical, pipe or other @P10K @Wooden `s iuenortine framewithinzth. outer 1- G91151fi0nefiiheh Serve -to ntereonneet appacasing to support the-innerioasinginisucnafway fetus Qonl edjyiiilntheinneneesine 0f netbieste interrupt neettrensferaloetween the ,oasines ioiesnid ennieeter Av vith devieesdisanf l therebyafford what is knownzes efsneetsbreek fof Sneh Gesine, toJoe f iisposed ,hetweerfthe cesings- However; thesemployment tiQn-thataeeess niaybeneedily had of such a Wooden frarneihas vnot been entir,e1y dffyeigCQnC?, Mid gOfnQ Stlh Connecsatisfaotory due ,to deterioration-of the wooden he) are AY.fn etweerithe` asingsrgd -Vlfrt'ameandthe expense, entailed in providing such ject :auxiliarytothe )foregoing ,is to ,a-rameand tiranniectnringI cabinets embodying nneotions of theaioresaid lcharaterto .-1 them. jjlt ,is therefore another important, object dryjaoent-atol'a rneinberf `extended pe- V of 4 this invention ,to sei-iabie, an inner casing tobe gesjpfnlgned openings. 'in ,the :supprtedwithin fan.y outer casingfin. al cabinet l .-of the y aforesaid character 1i1vfii', ho,x1i'. -resorting to s.; aWooden-or. other supporting frame.

fljlnei -l inner ,y and outerv asings on i, shells not.. a refrigerator V or like A,cabinetare provided with a aligned openings through which saccess.is ef qfoijded yto the-areaJ enclosedby they innencasing ,and such` openings -arerclosedpby the-:dooie mount- A-e d ongthe outer casing ische `movable toandirom closed position Withitespeottofthealienedopeninesintnefeesinss Wiiiieiitnesiieeniettemnted 1heretofore-:tofsnnnoftithefinnenoesineior-snell rPn- 1Sn9h/i99nne nsfwnether sneh `dev ieesare liwithinitheontenoesineior sttipsofmeterial innonsedwitnin; -without, the inner` sneu; of? a ternos'ed b@wennftheffwofasngsfnbfiut ihefedges 55 Qebneii-ftne nfnesad; character.

kies @then-2endituttheniobieets:or-theepresent-in- 'abeafsc vention are to provide attaching means on the inner and outer casings of a cabinet of the aforesaid character at spaced intervals and to interconnect such attaching means through the use of a relatively strong material possessing low heat conductive properties; to detachably interconnect .the inner and outer casings of a cabinet` of the aforesaid character and thereby facilitate installation, and removal where necessary, of the inner casing in a cabinet of the aforesaid character; and to so arrange the inner and outer casings of a cabinet of the aforesaid character and the arrangement for interconnecting such casings and supporting the inner casing from the outer casing that economy of construction and assembly may be realized as well as relatively high efficiency in the use of the cabinet.

Other and further objects of the present invention will be apparent from the following descripvtion and claims and are illustrated in the accom-.-

panying drawings which, by way of illustration show preferred embodiments and the principle thereof and what I now consider to be the best mode in which I have contemplated applying such principle. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as 4desired by those skilled in the art without departing from the present invention and the pur` view of the appended claims.

In the drawings:

Fig. 1 is a front elevational view of a cabinet embodying the present invention, and with the door removed;

Figs. 2, 3, and 4 are sectional views, drawn to an enlarged scale taken substantially and respectively on the lines 2 2, 3 3, and 4 4 on Fig. 1;

Fig. 5 is a detail front elevational view of the mid-portion of the longitudinal base-supporting member shown in Fig. 4;

Fig. 6 is a detail side elevational View of the front end portion of the transverse base-supporting member shown in Fig. 4;

Fig. 7 is a sectional view taken substantially on the line 1 1 in Fig. 4;

Figs. 8 and 9 are sectional views, drawn to the same scale as Figs. 2 to 4, taken substantially and respectively on the lines 8 8 and 9 9 on Fig. 1; and

Fig. 10 is a sectional view similar to Fig. 3 and showing a modified form of construction.

'The cabinet illustrated in the accompanying drawings comprises an outer casing or shell I0 having side walls II and I2, a top wall I3, and a rear wall I4. An opening I5 is provided in the upper portion of the front of the cabinet to permit access tothe interior of the cabinet, and this opening may be normally closed by a door (not shown). The outer casing I0 also has a front wall 'I 6 which extends downwardly from the lower edge portion of the opening I5, and a stand I1 supports the cabinet in such a manner that the side walls II and I2, rear wall I4 and the front wall I6, which are disposed vertically, terminate at their lower edges in spaced relation to the supporting surface or floor upon which the stand positioned below the lower edge of the opening I5.'

extends between the side walls II and I2 and the rear and front walls I4 and I6, respectively,

" andtogether with the lower portion of these walls lbetween the inner and outer shells.

forms a compartment I9 which, in my refrigerator cabinet, serves to house the mechanism (not shown) by which heat is abstracted from the coolant used to refrigerate the area within the inner casing of the cabinet which is described hereinafter. l

An inner casing or shell 20 having side walls 2| and 22, a top wall 23, a bottom wall 24, and a rear wall 25 is positioned within the outer casing I0 in such a manner that access to the inner casing 20 may be had through the opening I5. The inner casing 20 is smaller than the outer casing Il) soV as to be spaced therefrom and is supported by the outer casing I0 in a manner to be described hereinafter.

The outer shell I0 has a flange 26 extending `inwardly from the top wall I3 and the side walls II and I2 but not completely bridging the space The gap between the flange 26 and the inner shell 26 is bridged by plastic molding strips 21, the details of which will be described hereinafter. The corners are filled with preformed sections 28 and 28a which are connected to the strips by any suitable means such as screws 28h, and give the molding a pleasing appearance. The inner shell 26 is supported from the outer shell I0 by supporting members 29, 36, 3I, 32 and 32 which will be presently described in detail in this specification.

Referring now to Fig. 2, the supporting member 29 is comprised of a channel bracket 33 having a side 34 spot-welded or otherwise secured to the flange 26, a web 35 abutting the side wall I2 of the outer shell I0, and a side 36 extending into the space between the inner and outer shells. An angle bracket 31 is also provided within the space between the shells, and has a side 38 spotwelded or otherwise secured to inner shell I9 and a side 39 extending toward side 36 of channel bracket 33. As shown in Fig. 2, sides 39 and 36 are in the same plane but it is understood that they may be in different planes if desired. Connecting the sides 39 and 36 is a rigid strip of low heat conductant material 46 such as, for example, material which has been commercially produced from different raw materials such as bag-asse or Wood, the latter raw material being processed as taught in the Mason Patent No. 1,663,505, patented March 20, 1928, to afford a coherent grainless, hard, dense, stiff and strong product having practically all of the characteristics of natural wood, but of greater density and without grain. Said connecting strip 40 is secured by one or more rivets 4I to the side 36 and by one or more bolts 42 and nuts 43 to the side 39.

The front edge portion of the side walls 2| and 22, and the top wall 23, and bottom wall 24 of the inner casing 26 have an offset portion 44, and this offset portion 44 is connected to the flange 26 of the outer casing I0 by the plastic molding strips 21. The molding strips 21 may be made of textruded plastic and have a flat side 45 overlying offset region 44 of the inner casing 20 and a side 46 which is substantially perpendicular to the side 45. The side 46 has an offset portion 41 having a bifurcated end 48. One bifurcation 49 is shorter than the other and each bifurcation is curved inwardly at the end, and the space between the bifurcations is such that in placing the bifurcated end 48 of the plastic lstrip 21 in position to engage the flange 26, it is necessary for the flange 26 to wedge the bifurcations 49 and 50 apart which causes the bifurcations 49 and 50 to bear tightly against the flange 26 after the flange 26 has been positioned therebetween and thereby ramasse It "willl bev` observed that jthe positioning Aand `i "c'onstruction'pf the-:support- 29 -leavesfia -cl'ear ffspace I""through= the-*space -betweenfvthe inner mwallZ2-and' 'theputerwall I 2, definedA by :the-'conenecting "strip 5B #the offset f portion@ l4'4 of the-wall tioned electrical lines, and gas andliquidfcon- "':iitsof 'myrefrigeratonsuch' asj'for example-,- the A`i`three' wirerc'able* 52,1` and Vithe cold liquid-conduit L`"53'^andL a returniga-sconduit-54. By locatingithe'y fablelandconduits in 4the corner of the *space-'5 I *Fadjacenttothe-molding strip 27,*theyarefreadily imaccessible by -merely -^'removing the ^molding Mstripz'l.

fton'gue' 55""formed'i by "bending *overw asection of "fthes'ide" 38. Theton'gue 55 forms a support upon "f'which maybe' mounteda switchdforcontrolling a Alight or other accessories'of `thecabinet, -the "'swit'chi" 56 being 'attached to the tongue 55 in any "suitable lmanner v1such "as by"screws,' not shown, ""prthe like. The'f'proximity of the cable 52 `to ""'thef-tongue" 55"' facilitates''the connection 'fof the "switch5`6tothe cable.

It willbe observed" fromr Fig. 8 "that :the sup` "port"3 I 'is' constructed similarly'to thesupport 29. The" ton'gue`55a,^ however, is" used "'to support' a fidoor'. strike "51, *of 'any' suitable construction,4 by "means" of ma'chine screws' 58" passing `-through a lug 59 of lthedo'or strike'51,`the Inolding'strip', 'and' the "ffset'j portion 44'`of the' -inner-wall `2 I fiThe`Strike'illustrated'is adjustable Yby moving a "'c'atch" along serrations 6 I .to "the" desiredrpo'sition andthen tightening ascrew 62.

""Two" identical supports 32 are used as upper Supports in my cabinet and each is positioned in Y"acorner thereof. '.The supports 32 (Figs. 1v and 9) V"are also similarin `construction to the support 29 :except 'thatnoi tongue is formed on the angle M"bracket "311). TA space 5Ibi's defined between the,

*"ipperwalls I3and 23 in a'manner' similar to that whichi'the'space 5I is vdefined between the side "wvalls"'I2"and"22, and, adjacentV to the support 32 Y"lfpositionedtoward the right corner of the 4rertheniolding`"strip'21 between the space 5Ib ""ahdthenteriorofthe inner casing I9. A hous- "."ing""63 isiasten'erto the inner surface ofthe top vwall"""23, Fin communication withv the opening "form`ed""inthe" molding 4vstrip 2l, by means ofi- ""^screws 64, and the `cable 52 andthe conduits 53 Wand l54 may "be extended from the space 5I, thro'ughthe space 5Ib, the opening in the plastic f`strip"'f21'and^the housing 63'into the interior of "t'heinnerca'sing 24). The housing 63 may be of-'w fa-ny desired length necessary to support the cable 5152"and" the conduits `53 and 54f to the desired p0- "sition:within'` the inner casing 2B, and ispacked #-rwitht'a* suitable material 'surrounding the cable Hand-"conduits toeiect aseal between the interior of the-inner casing 2l] and the space 5Ib.

"Thebottomrwall/24 ofA inner shell 20 Amay be Y supportedfr'omfthe partition or panel I8 by the I'construction''shown in Figs. 1, 4, and 7. In this -fponstruction a pairof Yangle brackets 65 are secured-*to the rear portion of'partition I8 by spotwelding, or other suitable means, the pair of brackets V'beingpositionedto receive a strip B1 of iiigid'f'lovs'r*heat "conductant material such as the aforementioned' commercial` product processed in flaccordanceemthther/rasen@PatenwNo.211,663,505

The spacing -apart1of" the fang-le bracketsl565'fis such that they are slightly sprunglwhenzthestrip S'Ifis inplacef-so that therstripIis tightly gripped therebetweenf'and` securely held :inplace. The l"fronti end -portion- 61ahas arnotchlb'Sforrned therein. 'the purpose of which-will presently be explained.

l'A second stripof Yrigidlow heat conductant material, havingffawslot-'Iaf 'formed in ikthe-'midvportion thereof is positionedtransversely 'to' the stripe-61 `and hasits slot 68ainterlockedwiththe l notch '611). Two identical channel bracketsf vare attached to the Istrip 68, nearopposite': ends thereof,Av by riv'etsl'lll. The rivets .'III are Afastened to oneside 69aof the-bracket and the. otheriside BBD-thereof isV lfastened `.to the u inner. lsurfacemf 'the front -wall by` any e suitable vmeans such: asspot f-welding. Thel channel brackets 69 maybe-made v'in .one lpiecel or, Aas I prefer vand as isshownin lFig; 4; may -be .rn-ade: in two pieces-whichf-rarecon- `r nected togetherbyscrews .1 I ,sothat `the brackets "fmayebe easily disassembled, u iftdesired, andi-the 4strip removed.

4The bottomwall V.24 ofA the..nneri shell :20e-rests A `directly upon A- the ftop, edge-.610` of fthefstripl'l l-randthe top edge :68hofr'the istrip, and-isthus -`-Asupported'over the-greaterportion-of vits depth andlength.

The joint t between` f tlf-1e` lower :l wallf't 'orizthe iinner-casing@ and thel frontfwall-I 6 'orthetouter :casing `AI 0 diiers A from the constructionusediwith Arrelationzto thel supports .2 9., 3 I- and32: inithatrthe lat side 45a of-fthe moldingstrp 270i` is fastened lto vthe channel brackets .69 `by .means r otr screws .T2V rather than directlyv to-theifoiset .portion-.744 fofthelower wall24. "lThe-heads-of the screws wf'I2 vare counter-sunk into ther molding-strip'im and I the screws! 112 iextendi through the f molding Astrip 21m and the oisetportion 441 offthe bottem '-1 wallv 24 Mfand are screwed intothe channelbrackets passes in? the Offset portion M-.beingfofsuflicient fl size that direct-contact -betweenthe screw-L12 and have the offsetfportion 41.

The bottom l*wall -24 of the --inner Acasi r1g"-2Il is atta'ched`to *the* side and rear --w'allsthereof by Yajoint-Hk as :is-best seen in-Fig.54;and-theetop wall-23 is` 1like'wiserattached 4 tothe side'andrear V"'wallsiby'a similar joint (not shown) .Ani' opening "(not' shown) Ais provided'nthe horizontal :partition I3 .,througlr'whi-ch the cable 52;"and Ygas and liquid conduits""54` and'53vare Vpassed from the compartment I9 totheA 4,space 5I between the inner wall II and theputer-wall I2. ".The opening` is f formed in 'the partition I3 substantially in alignment Withl-the front inner corner Lof .the vspace V5 I` and isfpreferablysealed 5 aroundVV the cable 52 "andthe conduits "53 and* 54 to effect' aseal between the flower-housing-l9 and thespace 'between the inner and'outer shells.

`Itis-understood that the spacebetweenrthe j walls' of-'the innerfand Vouter shells is filled with a heat insulating material-MY suchas-rockf-wool or the like.

The modified `form "of construction `illustrated `inFigLflOis similarftol-that illustra-tedtin Figs.

1 to 9 inclusive, and like elements are indicated by the same reference number with the prefix l addedvthereto.

The difference between the construction shown in Fig. and the other gures is the difference between the plastic molding strips |21 and strips 21 and 21a. The molding strip |21 has, in addition to the bifurcated end |48, another bifurcated end |8I, having bifurcations |82 and |83, for engagement with the offset portion |44 of the inner wall |22, the construction and operation of which it is submitted will be obvious from consideration of Fig. 10 taken with the description heretofore set forth with respect to the construction and operation of the bifurcated end 48.

In placing the plastic molding strip |21 in position between the flange |26 of the outer wall l I2 and the reduced portion |44 of the inner wall |22 it is necessary to start one bifurcated end onto the flange it is to engage, as for example, the bifurcated end |48 onto the ilange |26, and then spring the other arm (in this case arm |45) inwardly until the inner bifurcation slips past the edge of the other ilange (in this case offset portion |44). The molding can then be moved into final position by pressing inwardly on the corner formed by the junction of the arm |45 and the arm |46 and thereby sliding the bifurcated ends |48 and |8| into final position on the flanges |26 and oifset portion |44, respectively.

It will be apparent from the foregoing description that the cabinet construction herein described requires no frame and that the support of the inner container from the outer lcontainer is effected by short strips 0f low heat-conductant material, and the heat losses through the support are thus minimized. Since the low heatconductant support is substantially impervious to moisture there is no danger of the support warping or rotting. The spacing of the support from the side walls leaves a clear space through which electric and iiuid lines may be passed from the refrigerant producing apparatus in the base to the heat abstracting apparatus within the cabinet. The plastic corner molding or facing seals the insulation in the space between the inner and outer shells and is readily removable to provide access to the electric and fluid lines.

Also, it will be noted that the present invention accomplishes its intended objects, some of which have been specifically referred to hereinbefore and others of which will be apparent from the foregoing description taken in conjunction with the accompanying drawings.

While I have illustrated and described selected embodiments of my invention, it is to be understood that these are capable of variation and modification and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A cabinet-comprising an outer shell, an in-` ner shell positioned within and supported by said outer shell in spaced relation thereto, said inner shell having a bottom wall, a substantially hori- Zontal partition positioned within said outer shell and supported thereby below said inner shell, a

pair of brackets attached to the upper surface of said partition, and means for supporting said inner shell from said outer shell and including a strip of low heat-conductant material extending between and slidably engaged by said pair of brackets and having an edge portion inl engagement with said bottom of said inner shell and another edge portion resting on said horizontal partition to be supported thereby, and said means also including a second strip of low heat conductant material extending at an angle to said rst mentioned strip and having an edge portion in engagement with said bottom of said inner shell and another edge portion resting on said horizontal portion to be supported thereby, at least one of said strips having a slot formed therein and the other of said strips being engaged in said slot.

2. A cabinet comprising an outer shell, an inner shell disposed within and spaced from said outer shell, said inner and outer shells having corresponding top, bottom and side Walls and openings at the front, a substantially horizontal partition disposed within and supported by said outer shell, brackets attached to the top and side Walls of the inner casing in spaced relation to the edge portion of said opening, brackets attached to the top and side walls of the outer casing in spaced relation to the edge portion of said opening, strips of low heat-conductant material disposed in spaced relation to said openings and interconnecting said brackets attached to the corresponding top and side walls of said inner and outer shells, supporting means attached to said partition, a strip of low heat-conductant material removably engaged with said supporting means and said partition and engaging said bottom wall of said inner shell, and a removable strip of low heat-conductant material connecting an edge portion of said outer shell to an edge portion of said inner shell, said last named strip having a bifurcated end portion adapted to receive said edge portion of said outer shell, and another bifurcated edge portion adapted to receive said edge portion of said inner shell.

3. A double-walled cabinet comprising spaced inner and outer shells having openings on corresponding sides thereof, a flange on the outer shell extending into the opening therein and substantially perpendicular to the terminal portion of said inner shell and spaced therefrom, said terminal portion having its free edge terminating inwardly from the plane of said flange, the free edge of said flange being spaced outwardly from the plane of said terminal portion, and a plurality of means for supporting the inner shell from the outer shell, each of said means comprising a bracket having a freeside parallel to said flange, a side secured to the flange in spaced relation to the free edge of said flange, and a side abutting the shell adjacent the flange; another bracket having a free side extending toward the freeI side of said first mentioned bracket; and a side secured to the inner shell in inwardly spaced relation to the free edge of said terminal portion; a low-heat conductant member having portions engaging the free sides of the brackets; and means securing the said engaging portions to the said free sides; and a strip of substantially rightangular cross section mounted on said flange and said terminal portion and having two bifurcated edges, said flange being disposed in one of said bifurcated edges, and said terminal portion being disposed in the other of said bifurcated edges.

4. A double walled cabinet as defined in claim 3 in which the inner legs of the two bifurcated edges have their longitudinal edge portionsy di- 'ected away from the outer legs.

5. A strip of low heat conductive material for sealing the opening between the inner and outer shells of a refrigerator cabinet, said strip being substantially right-angular in cross section and each web thereof having bifurcated edges extending throughout the length of each web, the inner leg of each bifurcated edge being shorter than the outer leg and having its free edge directed 5 away from the outer leg.

CARL EDWARD HARRY FRYKDAI-IL.

REFERENCES CITED UNITED STATES PATENTS Name Date Kilius et al Aug. 12, 1924 15 Number Number Number Name Date White July 18, 1939 King Oct. 17, 1939 Swedman Sept. 24, 1940 Quimper Sept. 2, 1941 Brouse Sept. 16, 1941 Howard Oct. 4, 1941 Lenning Apr. 7, 1942 Friedly Sept. 8, 1942 Armstrong Oct. 2, 1945 FOREIGN PATENTS Country Date Y Great Britain May 12, 1932 Germany Aug. 10, 1937 

